Illuminated push button switch assembly



Aug. 23, 1966 A. E. PRINCE 3,267,926

ILLUMINATED PUSH BUTTON SWITCH ASSEMBLY Filed July 27, 1964 3 Sheets-Sheet 1 24 2| i L j F IG. 2

7s 82 25 24 88 m 23 a5 Q 35 F s.l 4

FIG. 3

Al? THUR ENN/S PPM/(E l NVE N TOR BY [WATTQRNEY Aug.

A. E. PRINCE ILLUMINATED PUSH BUTTON SWITCH ASSEMBLY Filed July 27, 1964 96 no '16, 82 6| Z 5| 2 33 B 74 o O o W l/f/ M/ W) FIG. 4

5 Sheets-Sheet 2 FIG. 5

AR THUR ENNIS PRINCE INV E NTOR BY Wm ATTORNEY Aug. 23, 1966 A. E. PRINCE ILLUMINATED PUSH BUTTON SWITCH ASSEMBLY Filed July 27. 1964 3 Sheets-Sheet 5 FIG. 8

FIG. 9

AR THU? ENN/J PRINCE l NV E N T 0 R BY "36% ATTORNEY United States Patent 3,267,926 ILLUMINATED PUSH BIJ'ITGN SWITCH ASSEMBLY Arthur Ennis Prince, Succasunna, N.J., assignor to Otis Elevator Company, New York, N.Y., a corporation of New Jersey Filed Italy 27, 1964, Ser. No. 385,193 6 Ciaims. (6i. Zita-167) This invention relates generally to push button switches which afford a visible indication of their actuation and particularly to such switches m which the push button itself or an area adjacent thereto is illuminated upon actuation.

Push button switches are widely used in elevator installations both as ball landing buttons and as car buttons and in such service should have the following characteristics.

(1) The button or an adjacent area should become illuminated upon actuation.

(2) The illumination should be of suflicient intensity to afford a positive indication of actuation even under high level ambient light conditions.

(3) The indications should be visible from anywhere within a wide angle of view.

(4) The button should be easy to operate intentionally but diflicult to operate inadvertently.

(5) The lighted area should be uniformly illuminated.

(6) The light source should be adaptable to provide a wide selection of colors of light.

It would appear at first glance to be a simple matter to design a push button assembly having the above characteristics. However, when variou possible arrangements are considered in detail, it becomes apparent that the problem is not as simple as it at first appeared. For example, if the indicator lamp is separate from the button but placed adjacent thereto, it is obvious that considerable space is required. The space factor becomes important when many units are required to be placed on a small panel, as in the case of car buttons within an elevator car for selecting the desired floor. Additionally, the ready correlation between buttons and lamps requires spacing between units. Also it has been found that the public prefers an arrangement in which the button itself, or an area immediately surrounding the button, is illuminatcd.

As another example, suppose that the unit is designed so that the button itself is illuminated. If the button protrudes beyond the mounting surface, it is clearly visible but may readily be actuated inadvertently by persons or objects brushing against it. If the button is recessed, the chances of inadvertent operation are minimized but the visibility of the illumination is restricted to a small angle centered at a point directly in front of the button.

Considering another aspect of the problem, suppose an incandescent lamp is to be used for illumination. Such lamps can provide adequate illumination and, by using appropriate filters, can provide a wide range of colors. If the lamp is located directly behind the button, mechanical complications arise regarding the actuation of the switch. If the lamp be located behind but to one side of the button, it becomes difficult to provide uniform, spot free, illumination of the button. If a cold cathode tube be used for illumination, the light source may be located directly behind the actuating surface but both the intensity and the color of the light available from such tubes are severely limited.

It is a general object of the present invention to provide an improved illuminated push button switch assembly.

numeral or an arrow 26, as shown.

Another object is to provide a push button assembly having the aforementioned desirable characteristics.

Briefly stated, the invention comprises a hollow, generally cylindrical member of transparent material mounted in an aperture of the face plate. This member is formed with an annular flange extending beyond and engaging the front surface of the face plate. An opaque push button for actuating the switch is recessed in the flange to prevent inadvertent operation. Illumination of the flange is provided by an incandescent lamp mounted behind and to one side of the button. Light is transmitted substantially uniformly to all parts of the flange by a multi-faceted block of transparent material, such as methyl methacrylate, which encircles the cylindrical member and which is formed with a recess enclosing the lamp. Since the flange extends beyond the face plate, the illumination is clearly visible from anywhere within a wide field of view.

For a clearer understanding of the invention, reference may be made to the following detailed description and the accompanying drawing, in which:

FIGURE 1 is a front elevation view of the assembly as it appears when a single unit is installed;

FIGURE 2 is a side elevation view of the assembly;

FIGURE 3 is a view, partly in elevation and partly in section, taken on the line 33 of FIGURE 2;

FIGURE 4 is a cross-section view, taken on the line 4-4 of FIGURE 3;

FIGURE 5 is an enlarged view of a paratus shown in FIGURE 4;

FIGURE 6 is a pictorial view of a block of transparent material which is an element of the invention;

FIGURES 7, 8 and 9 are plan, elevation and bottom views respectively of the block shown pictorially in FIG- URE 6;

FIGURE 10 is an enlarged detail view of a portion of the apparatus shown in FIGURE 4;

FIGURE 11 is a cross-section view of a detail taken on the line 11i1 of FIGURE 10; and

FIGURE 12 is an electrical schematic diagram.

Referring first to FIGURE 1, a pair of bolts 21 and 22 support a face plate 23 from which protrudes an annular flange 24 made of transparent material. An opaque push button 25 is recessed Within the flange 24 and is marked with a suitable indication, such as a When the button 25 is depressed momentarily, the flange 24 becomes illuminated. Since the flange 24 extends beyond the surface of the face plate 23, the light from the flange 24 is visible even to persons standing far to one side.

Referring now to FIGURE 2, the bolts 21 and 22 pass through the face plate 23, spacing sleeves 27 and 28 and a mounting plate 29 to which they are fastened by nuts 31 and 32. A switch, indicated generally by the reference character 33, includes an insulating frame or body portion 34 and is fastened to the mounting plate 29 by means of a spring clip 35 which is fastened to the plate 29 by a pin 36. A lamp socket 37 is mounted on the switch 33 by means of mounting brackets 38 and 39 which, in turn, are fastened to the switch body 34 by bolts 41 and 42 and nuts 43 and 44. Connections to the socket 37 are made by lugs 45 and 46 to which are fastened flexible wires 47 and 48 which, in turn, are connected to terminals 51 and 52. Also shown in FIGURE 2 are screws 53 and 54 constituting terminals for the switch contacts. An opaque sleeve 55 surrounds those parts of the apparatus between the switch 33 and the face plate 23.

Referring now to FIGURE 3, a small incandescent lamp 57 is mounted in the socket 37 and projects above the body portion 34. The switch 33 includes an actuator 61 which, as best shown in FIGURES 4 and 5, is connected to a shaft 62 and both are urged upward by a portion of the apcompression spring 63 the lower end of which bears against an abutment 64 formed in the body portion 34. The shaft 62 is formed with a groove into which a retaining ring 65 is fitted. Just beneath the ring 65 is a washer 66 against which the upper end of the spring 63 bears. Upward movement of the shaft 62 and actuator 61 is limited by a flange portion 67 of the actuator 61 which bears against an abutment 68. Just above the retaining ring 65 is a cross arm 71 formed with a central aperture so that the arm 71 fits loosely around the shaft 62. A compression spring 72 acting between the arm 71 and the flange 67 urges the arm 71 downward. A pair of movable contacts 73 and 74 on opposite ends of the arm 71 are connected together electrically and cooperate with stationary contacts 75 and 76 connected to terminals 53 and 54 so that when the actuator 61 is depressed, a circuit is completed between the terminals 53 and 54.

The previously mentioned annular flange 24 extends outwardly from the rim of a generally cup shaped member 73 made of a transparent material such as clear cellulose acetate butyrate. Such material is commercially available under the trade name TENITE II. The member 78 may also be thought of as being shaped like a hollow cylinder with the flange 24 extending outwardly from one end and with the other end closed by a bottom wall 79. The member 78 fits into an aperture in the face plate 23 with a flange 24 engaging the front surface and the bottom extending toward the switch 33. The opaque disk shaped push button 25 is positioned within the member 78 and has a rod 81 fastened thereto. The rod 81 projects through a centrally located opening in the bottom wall 79 and extends to the actuator 61. With the parts in the positions shown, the push button 25 is recessed in the flange 24 and the rod 81 rests on the actuator 61.

A block 82 of transparent material extends approximately from the body portion 34 of the switch 33 to the face plate 23 and surrounds the sides and bottom Wall portion of the member 78. The block 82 is made of a transparent material such as methyl methacrylate, one satisfactory material being commercially available under the trade name LUCITE. The block 82 is of complex shape, the details being shown in FIGURES 3, 4 and 6-9. The block may be regarded as of generally cylindrical shape, including an outer curved surface and two bases, to which certain alterations have been made. The bases are not quite circular, but are extended along one radius, as shown in FIG. 9. The first base is formed with an outwardly extending rectangular flange 83 which bears against the rear surface of the face plate 23. The second base is positioned adjacent to, or just touching, the body portion 34- of the switch 33. The block 82 is formed with an axial bore 84 into which the rod 81 and the actuator 61 extend. This bore is enlarged at one side to form a recess 85 into which the lamp 57 extends. The outer curved surface to that side remote from the recess 85 and lamp 57 is cut away to form a plurality of facets or non parallel planar surfaces which cooperate with the curved surfaces in transmitting the light from the lamp 57 to all parts of the flange 24. More specifically, a first planar surface 86 extends approximately from the diameter of the second base in an inclined direction toward the first base. Three additional planar surfaces or facets 87, 88 and 89, each intersecting the surface 86, extend toward the first base but merge into the curved outer surface 91 before reaching the first base portion.

The purpose of the block 82 is to transmit light from the lamp 57 to all parts of the flange 24. The right side of the flange 24, as viewed in FIG. 3, can be illuminated by light transmitted substantially straight up, but in order to illuminate the left side of the flange 24, light must be transmitted around the opaque objects such as the actuator 61 and the rod 81 which occupy the central region. This is accomplished primarily by multiple internal reflections from the curved surface 91. Light is then reflected divergently upward by the facets 86, 87, 88 and 89 to the upper portion of the block 82. It has been found that in the absence of the planar surfaces, the flange 24 is illuminated irregularly and includes both dark portions and brightly illuminated portions. It has also been found that, in general, uniformity of illumination is improved as the number of facets is increased. The specific embodiment herein described including the four facets 86-89 affords remarkably uniform illumination of the flange 24 and whatever slight improvement that might be obtained by more facets is deemed unnecessary for present purposes.

The first base portion (the'upper portion as viewed in FIG. 3 which also includes the flange 83) is formed with a cylindrical recess 92 with a diameter slightly larger than the outside diameter of cup shaped member 78 and with a depth slightly greater than the distance by which the member 78 extends beyond the rear surface of the face plate 23. The surfaces of the recess 92 are roughened as by shot blasting so that the light transmitted through the block 82 to these surfaces will be diffused as it leaves the block 82. The flat bottom surface of the recess 92 is formed with two sockets or wells 93 and 94 which cooperate with mating projections or pins 95 and 96 extending from the bottom wall of the member 78.

As shown in FIGURES 3 and 4, the axial bore in the block 82 is of reduced size near the top. As shown in FIGURE 7, this portion of the bore is generally circular in cross section but includes four equally spaced radially extending grooves 101. As best shown in FIGURE 10, the member 78 and the block 82 are clamped together by a sleeve 162 formed with an outwardly extending flange 16 3 at the top which engages the surface of the bottom wall 79. The sleeve 102 is threaded at its bottom end to receive a nut 104 which bears against the block 82. The upper portion of the sleeve 102 is larger than the bottom and, as best shown in FIGURE 11, is formed with four projections 105 which mate with the grooves 101 to prevent the sleeve from rotating in the block 82. The inside surface of the sleeve 102 is formed with four corners 106 which define a square. As shown in FIG- URES 3, 4 and 10, the upper end 167 of the rod 81 is enlarged and of square cross section and makes a sliding fit in the corners 166 of the sleeve 102. Thus the rod 81 and the push button 25 are prevented from rotating in the sleeve .162. As best shown in FIG. 8, the block 82 is prevented from rotating by a stud 108 welded to the face plate 23 which passes through one of two apertures 109 in the flange 83, one or the other aperture being selected in accordance with the desired orientation of the apparatus.

The lower, circular portion of the rod 81 is formed with a groove which receives a retaining ring 1-10 which bears against the bottom of the sleeve 102 so as to limit the upward movement of the button 25. The opaque sleeve 55 is preferably made of white flexible opaque material such as a polyvinyl plastic and serves both to prevent light from leaking to an adjacent unit thereby forming an erroneous indication and to reflect light leaving the block 88- back into it.

The parts are assembled as shown with the cup shaped member 78 and the block 82 clamped together and to the face plate 23 and with the switch 36 clamped to the mounting plate 29. The spring 63 urges the shaft 62, the actuator 61, the rod 81 and the button 25 upward to the positions shown. The spring 72 urges the cross arm 71 downward into contact with the retaining ring 65. When the push button 25 is depressed, the retaining ring 65 and the washer 66 are moved downward against the urging of the spring 63, allowing the spring 72 to urge the movable contacts 73 and 74 into contact with the stationary contacts 75 and 76, thereby completing a circuit between the terminals 53 and 54.

The lamp 5? is lighted and the elevator control apparatus is actuated by a remotely located relay and its associated circuits. While such relays and circuits are conventional and form no part of the present invention,

one kind of circuit is shown schematically for illustrative purposes in FIGURE 12. A relay winding 111 operates several sets of contacts, including the normally open contacts 112 and 1 13. Power flows from the terminal marked through a normally closed switch 114 to the terminal 54. When the circuit between terminals 56 and 54 is completed momentarily, power flows to one terminal of the winding 111, the other terminal of which is grounded, thereby closing contacts 112 and 113. The contacts 112 complete a circuit around the terminals 53 and 54 so that the relay remains energized even although the circuit through the terminals 53- and 54 is broken. Closure of the contacts "113 completes a circuit from the source through the switch 114 to the terminal 52, thereby lighting the lamp 57. The remaining relay contacts may be used to actuate the elevator control apparatus. When the elevator car has answered the call, it opens the switch 114 thereby deenergizing the winding 1'11 and extinguishing the lamp 57.

When the lamp 57 is energized, light is transmitted to the interior of the block 82. The light is interiorly reflected by the curved cylindrical surface 9 1 and the facets 86-89 to the roughened surfaces of the recess 92 which diffuse the light as it leaves the block 82. The diffused light traverses the small space between the block 82 and the member 78, enters the member 78, and is transmitted to the flange 24 which is uniformly illuminated.

The incandescent lamp 57 provides an amount of light which is adequate to illuminate the flange 24 with suflicent intensity to be clearly visible even under high level ambient light conditions such as occur within an elevator car. Since the incandescent lamp 57 provides plenty of light, and since its radiation covers a wide spectrum, the flange 24 can be made to exhibit a wide variety of colors simply by including a suitable filter either as a separate item or by inclusion in the lamp envelope, the block 82 or the member 78.

Although a specific embodiment of the invention has been described in considerable detail for illustrative pur poses, many modifications can be made within the spirit of the invention. It is therefore desired that the protection afforded by Letters Patent be limited only by the true scope of the appended claims.

What is claimed is:

1. An illuminated push button switch assembly, comprising,

a face plate formed with an aperture,

a hollow member of transparent material disposed within and engaging the edges of said aperture and including an outwardly extending flange engaging the surface of said face plate,

said member protruding through said aperture on the side of said face plate opposite to said flange,

a switch mounted behind and spaced from that side of said member which is remote from said flange,

a push button recessed in said flange and operatively connected to said switch,

a lamp, and

means for transmitting light from said lamp to said flange, said means comprising,

a block of transparent material surrounding the protruding portion of said member and formed with a recess accommodating said lamp,

said block being formed with an exterior contour including a curved surface and a plurality of non parallel planar surfaces.

2. An illuminated push button switch assembly, coma face plate formed with a circular aperture,

a generally cylindrical hollow member of transparent material positioned within and engaging the edges of said aperture and formed with an outwardly extending annular flange engaging the surface of said face plate,

said member protruding through said aperture on the side of said face plate opposite to said flange,

a switch mounted behind and spaced from that side of said member which is remote from said flange,

a push butt-on recessed in said flange,

a rod connected to said button for operating said switch when said button is actuated,

a lamp radially displaced from said rod, and

a block of transparent material surrounding the protruding portion of said member and formed with a recess accommodating said lamp,

the exterior contour of said block on that side remote from said lamp including a plurality of mutually inclined planar surfaces.

3. An illuminated push button switch assembly, comprising,

a face plate formed with a circular aperture,

a generally cylindrical hollow member of transparent material positioned Within and engaging the edges of said aperture and formed with an outwardly extending annular flange engaging the surface of said face plate,

said member including a bottom wall formed with a centrally located opening,

a switch mounted behind said aperture in said face plate and spaced from said bottom wall,

a push button recessed in said flange,

a rod fastened to said button for operating said switch when said button is actuated,

a lamp mounted on said switch in displaced from said rod, and,

a block of transparent material generally occupying the space between said face plate and said switch,

said block including roughened surfaces surrounding the side and bottom walls of said member,

said block being formed with a bore surrounding said rod and a recess containing said lamp,

the exterior surface of said block in the region generally diametrically opposite said lamp including a plurality of non parallel planar surfaces inclined radially outward from said bore and axially toward said member.

4. An illuminated prising,

a face plate formed with an aperture,

a switch including a body and contacts mounted behind but spaced from said face plate,

said switch including an actuator for said contacts positioned coaxially with said aperture,

said actuator being spring biased in a direction toward said face plate,

a lamp mounted on said switch body in a position radially displaced from said actuator and projecting toward said face plate,

a generally cylindrical hollow member of transparent material including an annular flange extending radially outward from one end thereof and including a bottom wall, formed with a central opening, partially closing the other end thereof,

said member being positioned in said aperture with said flange engaging the front surface of said face plate and said bottom wall extending toward said switch,

an opaque disk shaped button positioned within said member,

a rod fastened to the center of said button and extending through said opening,

the length of said rod being selected to engage but not operate said actuator when said button is slightly recessed in said member, and

a generally cylindrical block of transparent material including an axial bore enclosing said rod and said actuator and including a firs-t recess in one end thereof surrounding the sides and said bottom wall of said member,

a position radially push button switch assembly, com- 7 said block being formed with a second recess extending from said bore and enclosing said lamp,

' the curved surface of said block in the region generally diametrically opposite the region enclosing said lamp being partially cut away to form a plurality of non parallel planar exterior surfaces inclined generally from said switch toward said member for directing light from said lamp through said block and said member to illuminate said flange substantially uniformly.

5. An illuminated push button switch assembly, comprising,

a face plate including front and rear surfaces formed with a circular aperture therein,

a generally cup shaped member of transparent material positioned in and protruding through said aperture,

said member including a rim and a bottom,

said rim being formed with an outwardly extending flange engaging the front surface of said face plate in the region surrounding said aperture,

said bottom being formed with a centrally located open- .a switch, including contacts, mounted in a position behind and spaced from said bottom of said member,

said switch including an actuator for operating said contacts located coaxially with but spaced from said opening in said bottom,

said actuator being spring biased in a direction toward said member for normally maintaining said contacts in one condition of operation,

an incandescent lamp mounted on said switch in a position radially displaced from said actuator and projecting toward said cup shaped member,

an opaque disk shaped push button Within said cup shaped member,

a rod fastened to said button projecting through said opening in said bottom toward said actuator and of such length as to fully depress said actuator before said button engages said bottom and to fully release said actuator while said button remains recessed in said member,

a generally cylindrical block of transparent material surrounding the sides and said bottom of said member and engaging said rear surface of said face plate,

said block being formed with an axial bore for accommoda-ting said rod and said actuator,

, said bore including a recess for accommodating said lamp,

said block being formed with an exterior surface which includes a curved portion and also a plurality of facets on that side which is remote from said lamp for directing light from said lamp substantially uniformly around the periphery of said flange,

means for fastening said block to said member, and,

a means fastened to said rod and cooperating with a portion of said block for limiting the movement of said button so as to retain said button recessed in said member.

6. An illuminated push button switch assembly, comprising,

a face plate including front and rear surfaces and formed with a circular aperture therein,

a generally cup shaped member of transparent material positioned in and protruding through said aperture,

said member including a rim and a bottom,

said rim being formed with an outwardly extending annular flange engaging said front surface of said face plate in the region surrounding said aperture,

said bottom being formed with a centrally located opena switch, including a body portion and contacts, mount ed behind and spaced from said bottom of said member,

an opaque disk shaped push button within said cup shaped member,

a rod for actuating said switch fastened to said button and projecting through said opening in said bottom,

an incandescent lamp mounted on said body portion of said switch in a location radially displaced'from said rod, and

a generally cylindrical block of transparent material including first and second base portions,

said first base portion being formed with an outwardly extending flange engaging said rear surface of said face plate,

said first base portion also being formed with a generally cylindrical recess having roughened surfaces and surrounding the protruding portion of said member,

said block being formed with an axial bore surrounding said rod,

said bore including a recess containing said lamp,

the exterior surface of said block in the region diametrically opposite said last named recess being formed with a first planar surface extending approximately from the diameter of said second base portion in an inclined direction toward said first base portion,

said exterior surface in said region of said block also being formed with a plurality of additional non parallel planar surfaces each intersecting said first surface.

References Cited by the Examiner UNITED STATES PATENTS 3,188,437 6/1965 Lauren et al 200-167 ROBERT K, SCHAEFER, Primary Examiner.

KATHLEEN H. CLAFFY, Examiner.

H. O. JONES, Assistant Examiner. 

1. AN ILLUMINATED PUSH BUTTON SWITCH ASSEMBLY, COMPRISING, A FACE PLATE FORMED WITH AN APERTURE, A HOLLOW MEMBER OF TRANSPARENT MATERIAL DISPOSED WITHIN AND ENGAGING THE EDGES OF SAID APERTURE AND INCLUDING AN OUTWARDLY EXTENDING FLANGE ENGAGING THE SURFACE OF SAID FACE PLATE, SAID MEMBER PROTRUDING THROUGH SAID APERTURE ON THE SAID OF SAID PLATE OPPOSITE TO SAID FLANGE, A SWITCH MOUNTED BEHIND AND SPACED FROM THE SIDE OF SAID MEMBER WHICH IS REMOTE FROM SAID FLANGE, A PUSH BUTTON RECESSED IN SAID FLANGE AND OPERATIVELY CONNECTED TO SAID SWITCH, A LAMP, AND MEANS FOR TRANSMITTING LIGHT FROM SAID LAMP TO SAID FLANGE, SAID MEANS COMPRISING, A BLOCK OF TRANSPARENT MATERIAL SURROUNDING THE PROTRUDING PORTION OF SAID MEMBER AND FORMED WITH A RECESS ACCOMMODATING SAID LAMP, SAID BLOCK BEING FORMED WITH AN EXTERIOR CONTOUR INCLUDING A CURVED SURFACE AND A PLURALITY OF NON PARALLEL PLANAR SURFACES. 